295 FORMATH Vol. 10 (2011): 295–308 Yield Prediction for Acacia mangium Plantations in Southeast Asia Matsumura, Naoto Keywords: Growth model, yield table, Acacia mangium, fast-growing tree species, Peninsular Malaysia Abstract: Acacia species have been widely planted in Southeast Asian indus- trial plantations. Among them, Acacia mangium—identified as a promising fast-growing variety—has been planted on a large scale not only for industrial use, but also for forest remediation in the tropics. This paper investigates the growth characteristics of Acacia mangium in Peninsular Malaysia to analyze its growth performance and construct a growth model and yield table applicable to Southeast Asia. Received January 6, 2011; Accepted February10, 2011
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295FORMATH Vol. 10 (2011): 295–308
Yield Prediction for Acacia mangiumPlantations in Southeast Asia
Matsumura, Naoto
Keywords: Growth model, yield table, Acacia mangium, fast-growing tree
species, Peninsular Malaysia
Abstract: Acacia species have been widely planted in Southeast Asian indus-
trial plantations. Among them, Acacia mangium—identified as a
promising fast-growing variety—has been planted on a large scale
not only for industrial use, but also for forest remediation in the
tropics. This paper investigates the growth characteristics of Acacia
mangium in Peninsular Malaysia to analyze its growth performance
and construct a growth model and yield table applicable to Southeast
Asia.
Received January 6, 2011; Accepted February10, 2011
296 Matsumura, Naoto
1. Introduction
Since the beginning of the 1970s, forested regions have been heavily
impacted by agricultural clearing, shifting cultivation, and excessive
harvesting, among many other factors. According to the FAO (2006)
world forest statistics, deforestation has become a serious global prob-
lem. Degradation of forest resources—the loss of structure, diversity,
function, and other qualitative features—is also an increasingly salient
issue, especially in tropical regions.
Many efforts have been made to restore and rehabilitate these trop-
ical forests, including artificial afforestation and reforestation. These
efforts have been hampered by difficulties related to seed and sapling
production, a problem that seems to be prevalent among tropical tree
species. A variety of research and local demonstration projects have
been completed, but yield prediction and management techniques for
tropical forests still have not been established, even in cases where
saplings have been successfully produced and survive an initial period
of growth.
Acacia mangium is one of several promising fast-growing tree species
in plantations on Peninsular Malaysia, Sabah, and Indonesia; it has also
shown a high survival rate in poorer soils. Recent experiments have
demonstrated basic conditions for the successful introduction of Acacia
mangium in tropical regions, as well as the application of appropriate
silvicultural treatments.
As a Clean Development Mechanism (CDM) for climate change mit-
igation, Acacia mangium plantations are expected to provide efficient
and profitable contributions to the sawlog and pulp markets. Partici-
pants in CDM projects are asked to provide key project parameters in
a project design document (PDD), which contains information about
the project activity, approved baseline methodology, etc. In this con-
text, the construction of a suitable yield table is quite important for
Yield Prediction for Acacia mangium Plantations in Southeast Asia 297
estimating potential sawlog and pulp yields, as well as verifying that
proposed projects meet CDM guidelines (Matsumura et al., 2008)
In this paper, we first construct a yield table for Acacia mangium
based on our study plots, followed by development of a growth model
and yield prediction. Using an analysis developed by Matsumura
(2004), we validate the proposed yield table’s diameter prediction.
2. Materials and methods
The sample plots used in our study are located on Peninsular
Malaysia (Fig.1). These plantation forests were allocated to the
compensatory forest plantation project (CFPP) with the goal of
converting degraded forestland into a plantation of fast-growing exotic
Acacia mangium for timber production. Stand-level data was obtained
from our field inventory; most stands were between 11 and 12 years
old, with the exception of a lowland plantation in Chikus where stand
age was between three and five years.
Figure 1. Data used for growth modeling
To compare and validate our growth model, we used yield tables
established in Sabah, East Malaysia and Sumatra, Indonesia. Growth
curves were taken from forest stand data collected in 1995 and 2006
298 Matsumura, Naoto
from a lowland Acacia mangium plantation growing in an area formerly
mined in Chikus, Perak (Inose, 1991, JICA, 1995, Fig.2).
Figure 2. Data used for regional comparison
Each site index is calculated on the basis of average height growth.
We estimated mean diameter growth, diameter variance, merchantable
volume, and other parameters needed for forest stand growth modeling.
Figure 3 and Table 1 show the conceptual flowchart used for the analysis
and the list of data used in our study.
Figure 3. Conceptual flowchart for volume estimation
Our yield table is derived from basic stand level growth parame-
ters, such as mean diameter at breast height (D), mean height (H),
merchantable height (HB), the number of trees (N), total basal area
Yield Prediction for Acacia mangium Plantations in Southeast Asia 299
Table 1. Analysis procedures and data used
(GF), and merchantable volume (V) (Wan Razali et al., 1989). To
calculate the growth prediction, we input height and diameter growth
data into the Mitscherlich equation. Stand inventory data from the
Chikus site was used to estimate the variance of height and diameter
growth over time; changes in these parameters can also be predicted by
the Mitscherlich equation. Note that the Mitscherlich equation is often
used as a monomolecular reaction equation and demonstrates relatively
high goodness of fit for tree diameter growth and its variance over time
(Suzuki, 1979).
Silvicultural treatments were completed following guidelines from the
Forestry Department of Peninsular Malaysia (FDPM), which included
an initial planting density of 900 seedlings per hectare and two thinning
treatments that each reduced stand density by approximately 30%. We
used an exponential function to describe the change in the number
300 Matsumura, Naoto
of trees over time. That is, the initial number of trees was set at
900 per ha and then decreased exponentially with each thinning. The
yield table derived from this procedure was compared with other tables
constructed by Matsumura and Ismail (1996) for stands in Sabah and
Sumatra.
3. Results
Basic forest stand growth elements, i.e. mean diameter at breast
height (D) and mean height (H), were calculated using least squares
estimation via the following Mitscherlich equations: